S NIP E / T UNIN G GUIDE
PREPARATION FOR RIG TUNING
SPREADER CHOICE
Spreader length and angle are the two areas where you can tune your
mast for crew weight and mast stiffness. Before stepping the mast,
these two items should be set up within the prescribed range. We
encourage the use of adjustable spreaders, as they make things easier.
SPREADER LENGTH
The length of the spreader controls the sideways bend of the mast.
Spreaders that are too long will push the middle of the mast to leeward,
which in turn clogs the jib slot and hurts pointing. Spreaders that are
too short allow the middle of the mast to pop to windward, robbing the
main of critical power. Because you want to hold onto as much sail power
as possible, try to keep the spreader length and angle at their largest
dimension.
These are recommended settings for a quick setup:
Because the Sidewinder Junior Mast is so flexible, we recommend using
15 7/8” x 30 1/2” with 1” of pre-bend. If the jib hits the spreader when
sailing upwind, pull the aft puller as much as a ½” behind neutral to keep
the jib just off the spreader.
With the spreaders in the mast and pulled aft to the stops, the length is
measured from the side of the mast to the shroud/spreader intersection.
We recommend measuring on the top of the spreader and looking for the
shortest distance from the mast to the shroud. The prescribed length
between the spreaders is 15 7/8”-16 3/4’’ (40cm-42.5cm).
If you are setting your spreaders for the first time, check the distance
between the shrouds at deck level. The standard length between the
shrouds is 4’ 7 1/2’’. If the length between your shrouds is different than
this, lengthen your spreaders 1/8” (3.1mm) for every 3/4’’ (1.9cm) farther
apart your shrouds are. If your shrouds are closer together, shorten the
spreader length by ⅛’’ (3.1mm).
SPREADER ANGLE
The angle of the spreader affects how much the mast will bend in
moderate-to-heavy air. A large angle will stiffen the mast, which is good
for a heavy crew or a soft mast. A smaller number will allow the mast to
bend more, which is good for a light crew or stiff mast.
The prescribed angle range is 29”-30 1/2” (73.6cm-77.5cm), measured at
the spreader tips from one shroud to the other with the spreaders locked
aft. If your spreaders need to be longer or shorter than standard, set
your tip-to-tip measurement when your spreaders are at the standard
length and then change the length of your spreaders evenly. The angle is
typically more important than the length between them.
It is imperative that the spreader angle be symmetrical to the centerline
of the boat. With the mast up, unhook the mast puller and pull on the
jib halyard hard so the spreaders swing back to their locked position
(check by lightly pulling the shroud aft), stand about 20’ to the side of the
boat, and line up the base of the two shrouds with your eye. Follow the
shrouds up to the spreader. If the shrouds are parallel and appear as one
shroud, your spreaders are set correctly. If you see one shroud going
forward and one aft, then adjust the screws until the shrouds look even
when viewed from the side of the boat.
PROCTOR MAST
SIDEWINDER
Mast length: 21’ 6”
Mast length: 21’ 6”
Spreaders: 16 7/8” x 29 3/4”
Spreaders: 16 3/4” x 29 1/2”
Summary of Contents for Snipe
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